Radio operating system and method for operating a radio system

ABSTRACT

A radio operating system, in particular for a medical device, comprises: a radio base station, provided for control of a device, an operating unit, for establishment of a radio connection with the radio base station, whereby the operating unit comprises a controller with a first threshold value (S 1 ) relating to a reception parameter (K), depending on which a switching between various operational modes (B 0 , B 1 ) for the operating unit is provided. On dropping below the threshold value (S 1 ), a safety-oriented operating mode (B 0 ) and, on exceeding the threshold value (S 1 ), a standard operating mode for the operating element ( 3 ), are provided. A first non-safety-critical command set (BS 1 ) may be activated by the operating unit and equally used in the various operating modes (B 0 , B 1 ), a second safety-critical command set (BS 2 ), activated by means of the operating unit, may be used in the safety-oriented operating mode (B 0 ) in a limited manner in comparison to the standard operating mode (B 1 ).

BACKGROUND

This application relates to a radio operating system, particularly foruse with a medical device, and to a method for operating the radiosystem.

For operating a device, especially a medical device, such as an X-raysystem, an operating control that is not stationary is often provided. Acable-connected operating control is known for instance from EuropeanPatent Disclosure EP 0 834 891 A2. From it, the possibility is alsoknown of linking an operating control to a central station in cordlessfashion, for instance via an infrared connection. A cordless connectioncan in principle also be made by means of radio communication. Incontrast to an infrared connection, no visual connection would benecessary between the operating control and the central station, or tothe device to be triggered. However, that has a disadvantage that aperson operating the equipment who, while carrying the operatingcontrol, is moving away from the device to be triggered could change thedevice settings by unintentionally tripping the operating control.Particularly in the case of medical devices, such an event can beextremely safety-critical. For safety-critical functions of medicaldevices, radio operations are therefore typically not used.

BRIEF SUMMARY

A radio system includes radio base station unit, which may be stationaryand an operating unit that may not be stationary; these may be termedthe units of the radio system. An expansion by an arbitrary number ofadditional stationary or portable units is also possible. Withoutrestricting the general applicability, the discussion herein will referto a single radio base station unit and a single operating unit, betweenwhich radio communication is to be established.

The radio communication between the units of the radio system can bemade in various operating modes. One of the units, which may be theoperating unit, has a control portion with a first threshold valuerelating to a reception parameter. The reception parameter, for instancea reception quality parameter, relates to the reception field intensity,or in the case of digital radio communication, may relate to the biterror rate of the data received. For classifying the reception quality,both of the reception field intensity and the bit error rate may beused. A measurement or estimate of the distance between the units of theradio system, which may also be used as the reception parameter, may beprovided directly by means of a transit time measurement, and/orindirectly by the evaluation of the reception quality. For simplicity,the terms “reception parameter” and “reception quality parameter” arealso used for cases in which the reception properties, in particular thereception quality, are characterized by a plurality of parameters.

Depending on whether the reception parameter, such as the receptionquality parameter, is greater than or less than the threshold value, thereception quality parameter, a standard operating mode or asafety-oriented operating mode of the radio system is activated.Information transmission in the radio system is possible by means of twodifferent command sets: a first, non-safety-critical command set and asecond, safety-critical command set. As long as the operation of theradio system is taking place in the standard operating mode, bothcommand sets are usable without restriction. Conversely, if a switchoveris made to the safety-oriented operating mode, for example, when thereception quality becomes worse, or the distance between the unitsincreases beyond the limit set by the threshold value, then only thefirst, non-safety-critical command set is usable without restrictions.Restrictions are automatically made in the safety-oriented operatingmode with respect to use of the second command set.

In an aspect, the second command set is blocked entirely in thesafety-oriented operating mode. However, the use of the second commandset may be possible in the safety-oriented operating mode, as long as aconfirmation input device, such as a confirmation key, is actuated. In afirst alternative, the use of the second command set is enabled onlyduring the period of actuation of the confirmation input device. In asecond alternative, by the actuation of the confirmation input device inthe safety-oriented operating mode, a time slot is initiated withinwhich all the command sets, and hence the full functional scope of thestandard operating mode, are enabled. In this circumstance, theconfirmation input device has the function of a trigger key. In anotheraspect, the time slot that has been initiated is reinitiated after thetermination of the operating function tripped by one of the command setsand is thus still open, in a further time interval, for subsequentoperation requirements with an arbitrary command set. This situation isadvantageous when an operating unit is embodied as a cordless pedalswitch.

Instead of separating the functions of the operating unit into twocommand sets from the standpoint of safety, a more finely graduatedclassification may be expedient, depending on the type of the device tobe triggered. For instance, for functions that for safety reasons shouldbe enabled in every case, especially emergency shutoff functions, to theextent they can be tripped by the operating unit, lower thresholds areset with regard to the required reception quality than for otheroperating functions required for the intended operation of the device.

A visual display of the active operating mode status, and particularlythe safety-oriented operating mode status, particularly at the operatingelement, may be provided. By the automatic activation of the visualdisplay, for instance in the form of a blinking lighted display, theuser is alerted, upon switchover from the standard operating mode to thesafety-oriented operating mode, and that the reception quality measuredas by the unit at its site is decreasing and/or the distance between theunits of the radio system are becoming greater. An acoustic warningreport may not be output until the user intentionally or unintentionallyactuates an input device, especially a key, of the operating unit, inwhich a function associated with the second, safety-critical commandset, is selected.

By means of the visual display, but without an acoustic report in thecase of a reception quality below the threshold value, the user carryingthe operating element is alerted, in a way that does not disturb otherpersons, that he/she is located at an extreme end of the communicationsrange. This also accommodates the situations where the range of theradio communication can be diminished by the various damping factors,such as many persons present in one room where the units of the radiosystem are also located. In such a case, if the reception parameterdrops below the threshold value, then the visual display should beunderstood as an indication to look for a more suitable site for systemoperation.

When the transit time of a signal forwarded between the units, insteadof the reception quality at the site of one of the units of the radiosystem, is at least primarily determinative for the reception parameter,it is possible, to limit the region in which radio communication betweenthe units is enabled without restriction. It is thus reliably possibleto preclude the tripping of safety-critical functions of the device in aradio-based operating environment, which is intended for operating astationary device set up in one room, by a unit in a neighboring room.

In an aspect, a second threshold value corresponding to a receptionparameter may be provided; if the reception parameter is less than thesecond threshold, the radio communication between the units is disabledor terminated. Regardless of whether the termination of the radiocommunication is based on the second threshold value or solely based ongiven physical conditions, especially an excessive distance between theunits, an acoustic report may be output that informs the user about thetermination of the radio communication. The threshold may not be fixed.This makes it possible to prevent a user from unintentionally carryingthe operating unit out of reception range, for instance in his/herpocket.

In a situation where there is complete or partial blocking of part ofthe functional scope of a radio-operated device, such as where the radioreception quality drops below the threshold value or a distance betweenunits is too great, as ascertained by transit time measurement, the useof the radio operating element remains limited in the desired way to thenear vicinity of the device, in particular the medical device, that isto be triggered.

BRIEF DESCRIPTION OF THE DRAWINGS

An example is described in further detail below with reference to thedrawings.

FIG. 1 shows a radio operating system for a medical device; and

FIG. 2, in a flow chart, shows various operating states of the radiooperating system of FIG. 1.

DETAILED DESCRIPTION OF THE DRAWINGS AND THE PRESENTLY PREFERREDEMBODIMENTS

Reference will now be made in detail to embodiments, but it will beunderstood that it is not intended to limit the invention to suchembodiments. In the following description, numerous specific details areset forth in order to provide a thorough understanding of the presentinvention which, however, may be practiced without some or all of thesespecific details. In other instances, well known process operations havenot been described in detail in order not to unnecessarily obscure thedescription.

As shown in FIG. 1, a radio operating system 1 includes a stationaryradio base station unit 2 and a portable operating unit 3. A medicaldevice 4 to be triggered, such as an X-ray system or lithotripsy system,is connected to the radio base station unit 2. The functional scope ofthe device 4 includes safety-relevant functions, such as switchingdrives or radiation sources, and functions that are not relevant tosafety, such as display functions. Both safety-critical andnon-safety-critical functions of the device 4 can be controlled by meansof the operating unit 3. Radio communication between the operating unit3 and the radio base station unit 2 is established by means of antennas5, 6; the maximum communications range is approximately 5 to 8 meters.The user actuating the operating unit 3 may work under the safety ruleof maintaining a visual connection with the device 4 to be triggered andthus, in general, also with the radio base station unit 2, which may beinstalled on or in the device 4. In an aspect, should the radio basestation 2 be covered by a cloth hanging down from an examination table,there may be practically no impairment to the radio communication, whichis shown in dashed lines and marked FV. In this aspect, the radiocommunication between the radio base station unit 2 and the operatingunit 3 offers significant advantages, for instance, over an infraredconnection. On the other hand, however, the possibility that the user byunintentionally actuating the operating unit 3 without visual contactwith the device 4, for instance in an antechamber to the examinationchamber or to the operating room where the device 4 is set up, andundesirably activate functions of the device 4 cannot be precluded. Thisdanger is effectively counteracted by operating the operating unit 3 inoperating modes B0, B1, described in further detail below, and also withreference to the flow chart of FIG. 2.

The operating unit 3 has a radio module 7, which furnishes informationabout the field intensity, measured by means of the antenna 5, and aboutthe bit error rate of the received data to a control portion(“controller”) 8. In addition or as an alternative, the distance betweenthe antennas 5, 6 of the units 2, 3 is ascertained by transit-timemeasurement in the radio operating system 1.

The controller 8 is also connected to a keypad 9, a keypad controller10, and a speaker 11 as an acoustic output device. In an example, keypad9 includes four function keys F1, F2, F3, and F4. The designations F1through F4 represent the functions of the device 4 that can be triggeredby the operating unit 3. In this example, the functions F1, F2 areassigned to a first, non-safety-critical command set BS1, and thefunctions F3, F4 are assigned to a second, safety-critical command setBS2. As long as the user carrying the operating unit 3 is within thecommunications range of the system, and no significant shields are inthe way, all the functions F1 through F4 are enabled withoutrestriction: the operating unit 3 is in the standard operating mode B1.

As the distance between the operating element 3 and the radio basestation 2 increases, and/or if there are shields between the units 2, 3,for instance in the form of a wall in a building, the reception qualityof the data stream originating at the radio base station unit 2, whichquality is detectable by means of the antenna 5 of the operating unit 3,becomes worse. The reception quality at the operating unit 3 isconverted, by measuring the field intensity and/or ascertaining the biterror rate, into at least one reception quality parameter (“receptionparameter” or “reception quality parameter”) K, which serves thecontroller 8 as an input variable. Alternatively, the receptionparameter K is a measure of the distance between the units 2, 3 of theradio system, and a decreasing reception parameter K corresponds to anincreasing spacing between the units 2, 3. The controller 8 compares theparameter K, generated by the radio module 7, with a first thresholdvalue S1.

The allocation of functions into the radio module 7 on the one hand andthe controller 8 on the other should be understood as merely symbolic. Aplurality or all of the components, that is, the radio module 7,controller 8 and keypad controller 10, may be realized as one integralcomponent, and both open-and closed-loop control functions can also beattained by software. It is equally possible as an alternative, forfunctions shown symbolically inside the operating unit 3 also to beintegrated with the radio base station unit 2 and/or the device 4.

If the reception parameter K is less than the first threshold value S1,a further, safety-oriented operating mode B0 is activated. The functionsF1, F2 associated with the first, non-safety-critical command set BS1are enabled without change. However, the functions F3, F4 associatedwith the second, safety-critical command set BS2 are not usable merelyby actuating the corresponding keys of the operating unit 3. Instead, toenable the safety-critical functions F3, F4, the actuation of an enabledkey 12, as a confirmation input device, is required.

In a first alternative, the use of the functions F3, F4 of thesafety-critical command set BS2 is enabled only so long as the enablekey 12 continues to be depressed. In a second alternative, the fullfunctional scope of the standard operating mode B1 that includes bothcommand sets BS1, BS2 is enabled, for instance for a period of 10seconds, by a brief actuation of the enable key 12. The user is informedof the necessity of actuating the enable key 12 by an acoustic warningsignal output by the speaker 11, as soon as the user selects one of thefunctions F3, F4 in the safety-oriented operating mode B0 without havingfirst enabled the functions. In this way, the user is precluded fromunintentionally tripping a safety-critical function of the device 4. Therestricted use of functions, only after actuation of the enable key 12for the safety-critical command set BS2 in the safety-oriented operatingmode B0, is symbolized in FIG. 2 by the term BS2.

When the user, carrying the operating unit 3, moves out of the nearvicinity of the radio base station 2 within which the standard operatingmode B0 is possible, an acoustic warning is not automatically given. Thesafety-oriented operating mode B0 activated and the activation of thesafety-oriented operating mode B0 is displayed by a light-emitting diode13 as a visual display device in an undisturbing way. If only thefunctions F1, F2 associated with the non-safety-critical command set BS1are selected, no acoustic warning is made. But, the user is informed ofthe fact that he/she is located in a region of reduced reception fieldintensity and/or an increased bit error rate by the visual display. Inthis way, great user friendliness of the radio operating system 1 isprovided.

If the operating unit 3 is moved farther from the radio base stationunit 2, or the reception quality of the location of the antenna 5 isfurther reduced in some other way, then the parameter K drops below athreshold value S2 specified in the controller 8. In that case, all thefunctions F1 through F4 are blocked. Information to the user isaccordingly provided by an acoustic warning, output via the speaker 11.The acoustic signal may be, for instance, a defined sequence of tones,or speech output. If the operating unit 3, in addition to the keypad 9,or combined with the operating unit 3, may also have an optical outputdevice, for instance in the form of a touch sensitive display screen,then the output of an visual report, for instance in the form of a cleartext display, may be provided in addition or alternatively to theacoustic warning.

Although the present invention has been explained by way of the examplesdescribed above, it should be understood to the ordinary skilled personin the art that the invention is not limited to the examples, but ratherthat various changes or modifications thereof are possible withoutdeparting from the spirit of the invention. Accordingly, the scope ofthe invention shall be determined only by the appended claims and theirequivalents.

1. A radio operating system, comprising: a radio base station unitconfigured to control a device; and an operating unit in communicationwith the radio base station unit, wherein a selection is providedbetween a plurality of operating modes of the operating unit, theselection corresponding to a value of a reception parameter with respectto a threshold value; when the reception parameter value is less thanthe threshold value, a safety-oriented operating mode is selected and ifthe reception parameter is greater than the threshold value a standardoperating mode is selected; a first, non-safety-critical command set,activatable by means of the operating unit, is usable in each of theoperating modes; a second, safety-critical command set (BS2),activatable by means of the operating unit, is usable in thesafety-oriented operating mode, when the second command set has isenabled.
 2. The radio operating system as in claim 1, wherein actuationof a confirmation input device, enables the safety-critical command set.3. The radio operating system as in claim 1, wherein the operating unithas a display device provided for displaying the operating mode.
 4. Theradio operating system as in claim 1, wherein the operating unit has anacoustic output device.
 5. The radio operating system as in claim 1,wherein when the reception parameter is less than a second thresholdvalue the radio connection between the operating unit and the radio basestation unit is disabled.
 6. A method for operating a radio systemhaving at least two units, comprising: measuring the transmissionquality of the radio communication between the units to determine of areception parameter; comparing a value of the reception parameter with athreshold value; selecting one of a plurality of operating modes as afunction of the value of the reception parameter with respect to thethreshold value, wherein safety-oriented operating mode is selected ifthe value of the reception parameter is less than the threshold andstandard operating mode is selected if the value of the receptionparameter is greater than the threshold; providing a first,non-safety-critical command set, and a second, safety-critical commandset enabling the use of both command sets in the standard operatingmode; and enabling the first command set in the safety-orientedoperating mode, and restricting the use of the second command set. 7.The method as recited in claim 6, wherein the standard operating mode isenabled in the safety-oriented operating mode by actuation of aconfirmation input device.
 8. The method as in claim 7, wherein the useof the standard operating mode is enabled in the safety-orientedoperating mode during the period of actuation of the confirmation inputdevice.
 9. The method as in claim 7, wherein the actuation of theconfirmation input device in the safety-oriented operating mode opens atime slot within which the standard operating mode is enabled.
 10. Themethod as in claim 6, wherein upon switchover from the standardoperating mode to the safety-oriented operating mode, an optical reportis output.
 11. The method as in claim 6, wherein when a functionassociated with the safety-critical command set is chosen in thesafety-oriented operating mode, an acoustic signal is output.
 12. Themethod as in claim 6, wherein if the radio communication between theparties is disabled because of the transmission quality, an acousticsignal is output.
 13. The method as in claim 6, wherein the receptionparameter contains information representing the reception quality of theradio communication between the units.
 14. The method as in claim 13,wherein the reception parameter contains information representing thereception field intensity at the location of one of the units.
 15. Themethod as in claim 13, wherein the reception parameter includesinformation representing the bit error rate of the radio communicationbetween the units.
 16. The method as in claim 6, wherein the receptionparameter includes information representing the distance between theunits.
 17. The method as in claim 16, wherein the reception parameter isascertained by transit time measurement.
 18. The radio operating systemas in claim 2, wherein the operating unit has a display device providedfor displaying the operating mode.
 19. The radio operating system as inclaim 2, wherein the operating unit has an acoustic output device. 20.The radio operating system as in claim 19, wherein when the receptionparameter is less than a second threshold value the radio connectionbetween the operating unit and the radio base station unit is disabled.21. The method as in claim 7, wherein upon switchover from the standardoperating mode to the safety-oriented operating mode, an optical reportis output.
 22. The method as in claim 7, wherein when a functionassociated with the safety-critical command set is chosen in thesafety-oriented operating mode, an acoustic warning is output.
 23. Themethod as in claim 7, wherein if the radio communication between theparties is disabled because of the transmission quality, an acousticsignal is output.
 24. The method as in claim 7, wherein the receptionparameter contains information representing the reception quality of theradio communication between the units.